Where $JRE_cacerts is the path to the JRE's certs
file. It's location may differ depending on the Operating
System, but its typically called cacerts and located at
$JAVA_HOME/lib/security/cacerts.
It can be under a different directory in
$JAVA_HOME. The default password
is changeit.

Java programs, including the Oozie client, can now connect to
the Oozie Server using the self-signed certificate.

In the connection strings change HTTP to HTTPS, for example, replace
http://oozie.server.hostname:11000/oozie with
https://oozie.server.hostname:11443/oozie.